First off, the wine wasn't made to last for a quarter of a century. Secondly it hasn't been for sale in the open market for roughly 20 years. And finally, CB was not a collectable brand that collectors are likely to be offering or that rare wine merchants would stock. If you found a bottle it would be a real fluke.

And you can't go to the winery to see if they have some in the library, because it doesn't exist anymore. Heublein bought it and phased it out very rapidly...sold the great old vineyards to this one and that one. The only thing that's left of the brand is brandy (mostly imported stuff) and a few dessert wines.

One more thought for you, though. St. Mary's College in Moraga CA is run by the Christian Brothers. For many years they had a library of sorts of older wines. While you may not find what you are looking for, it might be worth a phone call. You might want to ask one someone in the Alumni office. I believe a gentleman named Giles Miller runs the office. The area code is 925 but the actual number eludes me just now.